1. Field of the Invention
This invention relates to landing gears or props on semi-trailers, and more particularly to a means of securing a landing gear leg to the trailer crossmembers.
2. Description of the Prior Art
It is known in the prior art to secure the landing gear legs of a semi-trailer to the underside of the trailer crossmembers with thin vertical mounting brackets or blades having reinforcing flanges around their perimeters. This has generally provided sufficient support for the landing gear legs. However, because severe vertical forces must be transferred through the top portion of the flange to the crossmembers, additional reinforcement of the top portion of the flange has been required to prevent material failure of the flange and consequently collapse of the landing gear.
One method of reinforcing the flange is shown in the patent to John J. Glassmeyer, U.S. Pat. No. 3,807,756 and incorporated by reference herein. More particularly, the landing gear structure of that patent includes an inverted L-shaped structural angle which is welded or bolted to the top edge of the mounting bracket and the crossmembers it supports. Another method of reinforcement has been to increase the material thickness of the mounting bracket. Although both of these methods provide reinforcement for the landing gear brackets, they substantially increase the weight, complexity of manufacture and maintenance, and consequently the cost of the semi-trailer landing gear.
The prior art landing gear structure discussed above also includes a hand crank which can be rotated to raise or lower the landing gear legs. The hand crank is secured to a crankshaft extending between the gear legs and outwardly from one side of the trailer through an aperture in the mounting bracket. However, because of the reinforcing structure necessary to insure the rigidity and load bearing capacity of the bracket, it has been necessary to minimize the diameter of the aperture in the bracket. Furthermore, since the location of the crankshaft and associated gearing mechanism with respect to the bracket varies between different makes and types of gearing mechanisms, each landing gear bracket has generally been limited to use with a particular make of gearing mechanism. Consequently, the interchangeability of various gearing mechanisms between different landing gears has been very restricted and has required substantial modification of the bracket structure.
The present invention provides a novel universal bracket structure which overcomes these difficulties.